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1 /*
2 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_bit.h"
21 #include "xfs_log.h"
22 #include "xfs_inum.h"
23 #include "xfs_trans.h"
24 #include "xfs_sb.h"
25 #include "xfs_ag.h"
26 #include "xfs_dir2.h"
27 #include "xfs_alloc.h"
28 #include "xfs_dmapi.h"
29 #include "xfs_quota.h"
30 #include "xfs_mount.h"
31 #include "xfs_bmap_btree.h"
32 #include "xfs_alloc_btree.h"
33 #include "xfs_ialloc_btree.h"
34 #include "xfs_dir2_sf.h"
35 #include "xfs_attr_sf.h"
36 #include "xfs_dinode.h"
37 #include "xfs_inode.h"
38 #include "xfs_bmap.h"
39 #include "xfs_btree.h"
40 #include "xfs_ialloc.h"
41 #include "xfs_rtalloc.h"
42 #include "xfs_error.h"
43 #include "xfs_itable.h"
44 #include "xfs_rw.h"
45 #include "xfs_acl.h"
46 #include "xfs_cap.h"
47 #include "xfs_mac.h"
48 #include "xfs_attr.h"
49 #include "xfs_inode_item.h"
50 #include "xfs_buf_item.h"
51 #include "xfs_utils.h"
52 #include "xfs_iomap.h"
53
54 #include <linux/capability.h>
55 #include <linux/writeback.h>
56
57
58 #if defined(XFS_RW_TRACE)
59 void
60 xfs_rw_enter_trace(
61 int tag,
62 xfs_iocore_t *io,
63 void *data,
64 size_t segs,
65 loff_t offset,
66 int ioflags)
67 {
68 xfs_inode_t *ip = XFS_IO_INODE(io);
69
70 if (ip->i_rwtrace == NULL)
71 return;
72 ktrace_enter(ip->i_rwtrace,
73 (void *)(unsigned long)tag,
74 (void *)ip,
75 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
76 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
77 (void *)data,
78 (void *)((unsigned long)segs),
79 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
80 (void *)((unsigned long)(offset & 0xffffffff)),
81 (void *)((unsigned long)ioflags),
82 (void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
83 (void *)((unsigned long)(io->io_new_size & 0xffffffff)),
84 (void *)((unsigned long)current_pid()),
85 (void *)NULL,
86 (void *)NULL,
87 (void *)NULL,
88 (void *)NULL);
89 }
90
91 void
92 xfs_inval_cached_trace(
93 xfs_iocore_t *io,
94 xfs_off_t offset,
95 xfs_off_t len,
96 xfs_off_t first,
97 xfs_off_t last)
98 {
99 xfs_inode_t *ip = XFS_IO_INODE(io);
100
101 if (ip->i_rwtrace == NULL)
102 return;
103 ktrace_enter(ip->i_rwtrace,
104 (void *)(__psint_t)XFS_INVAL_CACHED,
105 (void *)ip,
106 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
107 (void *)((unsigned long)(offset & 0xffffffff)),
108 (void *)((unsigned long)((len >> 32) & 0xffffffff)),
109 (void *)((unsigned long)(len & 0xffffffff)),
110 (void *)((unsigned long)((first >> 32) & 0xffffffff)),
111 (void *)((unsigned long)(first & 0xffffffff)),
112 (void *)((unsigned long)((last >> 32) & 0xffffffff)),
113 (void *)((unsigned long)(last & 0xffffffff)),
114 (void *)((unsigned long)current_pid()),
115 (void *)NULL,
116 (void *)NULL,
117 (void *)NULL,
118 (void *)NULL,
119 (void *)NULL);
120 }
121 #endif
122
123 /*
124 * xfs_iozero
125 *
126 * xfs_iozero clears the specified range of buffer supplied,
127 * and marks all the affected blocks as valid and modified. If
128 * an affected block is not allocated, it will be allocated. If
129 * an affected block is not completely overwritten, and is not
130 * valid before the operation, it will be read from disk before
131 * being partially zeroed.
132 */
133 STATIC int
134 xfs_iozero(
135 struct inode *ip, /* inode */
136 loff_t pos, /* offset in file */
137 size_t count, /* size of data to zero */
138 loff_t end_size) /* max file size to set */
139 {
140 unsigned bytes;
141 struct page *page;
142 struct address_space *mapping;
143 char *kaddr;
144 int status;
145
146 mapping = ip->i_mapping;
147 do {
148 unsigned long index, offset;
149
150 offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
151 index = pos >> PAGE_CACHE_SHIFT;
152 bytes = PAGE_CACHE_SIZE - offset;
153 if (bytes > count)
154 bytes = count;
155
156 status = -ENOMEM;
157 page = grab_cache_page(mapping, index);
158 if (!page)
159 break;
160
161 kaddr = kmap(page);
162 status = mapping->a_ops->prepare_write(NULL, page, offset,
163 offset + bytes);
164 if (status) {
165 goto unlock;
166 }
167
168 memset((void *) (kaddr + offset), 0, bytes);
169 flush_dcache_page(page);
170 status = mapping->a_ops->commit_write(NULL, page, offset,
171 offset + bytes);
172 if (!status) {
173 pos += bytes;
174 count -= bytes;
175 if (pos > i_size_read(ip))
176 i_size_write(ip, pos < end_size ? pos : end_size);
177 }
178
179 unlock:
180 kunmap(page);
181 unlock_page(page);
182 page_cache_release(page);
183 if (status)
184 break;
185 } while (count);
186
187 return (-status);
188 }
189
190 ssize_t /* bytes read, or (-) error */
191 xfs_read(
192 bhv_desc_t *bdp,
193 struct kiocb *iocb,
194 const struct iovec *iovp,
195 unsigned int segs,
196 loff_t *offset,
197 int ioflags,
198 cred_t *credp)
199 {
200 struct file *file = iocb->ki_filp;
201 struct inode *inode = file->f_mapping->host;
202 size_t size = 0;
203 ssize_t ret;
204 xfs_fsize_t n;
205 xfs_inode_t *ip;
206 xfs_mount_t *mp;
207 bhv_vnode_t *vp;
208 unsigned long seg;
209
210 ip = XFS_BHVTOI(bdp);
211 vp = BHV_TO_VNODE(bdp);
212 mp = ip->i_mount;
213
214 XFS_STATS_INC(xs_read_calls);
215
216 /* START copy & waste from filemap.c */
217 for (seg = 0; seg < segs; seg++) {
218 const struct iovec *iv = &iovp[seg];
219
220 /*
221 * If any segment has a negative length, or the cumulative
222 * length ever wraps negative then return -EINVAL.
223 */
224 size += iv->iov_len;
225 if (unlikely((ssize_t)(size|iv->iov_len) < 0))
226 return XFS_ERROR(-EINVAL);
227 }
228 /* END copy & waste from filemap.c */
229
230 if (unlikely(ioflags & IO_ISDIRECT)) {
231 xfs_buftarg_t *target =
232 (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) ?
233 mp->m_rtdev_targp : mp->m_ddev_targp;
234 if ((*offset & target->bt_smask) ||
235 (size & target->bt_smask)) {
236 if (*offset == ip->i_d.di_size) {
237 return (0);
238 }
239 return -XFS_ERROR(EINVAL);
240 }
241 }
242
243 n = XFS_MAXIOFFSET(mp) - *offset;
244 if ((n <= 0) || (size == 0))
245 return 0;
246
247 if (n < size)
248 size = n;
249
250 if (XFS_FORCED_SHUTDOWN(mp))
251 return -EIO;
252
253 if (unlikely(ioflags & IO_ISDIRECT))
254 mutex_lock(&inode->i_mutex);
255 xfs_ilock(ip, XFS_IOLOCK_SHARED);
256
257 if (DM_EVENT_ENABLED(vp->v_vfsp, ip, DM_EVENT_READ) &&
258 !(ioflags & IO_INVIS)) {
259 bhv_vrwlock_t locktype = VRWLOCK_READ;
260 int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags);
261
262 ret = -XFS_SEND_DATA(mp, DM_EVENT_READ,
263 BHV_TO_VNODE(bdp), *offset, size,
264 dmflags, &locktype);
265 if (ret) {
266 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
267 if (unlikely(ioflags & IO_ISDIRECT))
268 mutex_unlock(&inode->i_mutex);
269 return ret;
270 }
271 }
272
273 if (unlikely((ioflags & IO_ISDIRECT) && VN_CACHED(vp)))
274 bhv_vop_flushinval_pages(vp, ctooff(offtoct(*offset)),
275 -1, FI_REMAPF_LOCKED);
276
277 if (unlikely(ioflags & IO_ISDIRECT))
278 mutex_unlock(&inode->i_mutex);
279
280 xfs_rw_enter_trace(XFS_READ_ENTER, &ip->i_iocore,
281 (void *)iovp, segs, *offset, ioflags);
282 ret = __generic_file_aio_read(iocb, iovp, segs, offset);
283 if (ret == -EIOCBQUEUED && !(ioflags & IO_ISAIO))
284 ret = wait_on_sync_kiocb(iocb);
285 if (ret > 0)
286 XFS_STATS_ADD(xs_read_bytes, ret);
287
288 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
289 return ret;
290 }
291
292 ssize_t
293 xfs_sendfile(
294 bhv_desc_t *bdp,
295 struct file *filp,
296 loff_t *offset,
297 int ioflags,
298 size_t count,
299 read_actor_t actor,
300 void *target,
301 cred_t *credp)
302 {
303 xfs_inode_t *ip = XFS_BHVTOI(bdp);
304 xfs_mount_t *mp = ip->i_mount;
305 ssize_t ret;
306
307 XFS_STATS_INC(xs_read_calls);
308 if (XFS_FORCED_SHUTDOWN(mp))
309 return -EIO;
310
311 xfs_ilock(ip, XFS_IOLOCK_SHARED);
312
313 if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_READ) &&
314 (!(ioflags & IO_INVIS))) {
315 bhv_vrwlock_t locktype = VRWLOCK_READ;
316 int error;
317
318 error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp),
319 *offset, count,
320 FILP_DELAY_FLAG(filp), &locktype);
321 if (error) {
322 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
323 return -error;
324 }
325 }
326 xfs_rw_enter_trace(XFS_SENDFILE_ENTER, &ip->i_iocore,
327 (void *)(unsigned long)target, count, *offset, ioflags);
328 ret = generic_file_sendfile(filp, offset, count, actor, target);
329 if (ret > 0)
330 XFS_STATS_ADD(xs_read_bytes, ret);
331
332 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
333 return ret;
334 }
335
336 ssize_t
337 xfs_splice_read(
338 bhv_desc_t *bdp,
339 struct file *infilp,
340 loff_t *ppos,
341 struct pipe_inode_info *pipe,
342 size_t count,
343 int flags,
344 int ioflags,
345 cred_t *credp)
346 {
347 xfs_inode_t *ip = XFS_BHVTOI(bdp);
348 xfs_mount_t *mp = ip->i_mount;
349 ssize_t ret;
350
351 XFS_STATS_INC(xs_read_calls);
352 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
353 return -EIO;
354
355 xfs_ilock(ip, XFS_IOLOCK_SHARED);
356
357 if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_READ) &&
358 (!(ioflags & IO_INVIS))) {
359 bhv_vrwlock_t locktype = VRWLOCK_READ;
360 int error;
361
362 error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp),
363 *ppos, count,
364 FILP_DELAY_FLAG(infilp), &locktype);
365 if (error) {
366 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
367 return -error;
368 }
369 }
370 xfs_rw_enter_trace(XFS_SPLICE_READ_ENTER, &ip->i_iocore,
371 pipe, count, *ppos, ioflags);
372 ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
373 if (ret > 0)
374 XFS_STATS_ADD(xs_read_bytes, ret);
375
376 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
377 return ret;
378 }
379
380 ssize_t
381 xfs_splice_write(
382 bhv_desc_t *bdp,
383 struct pipe_inode_info *pipe,
384 struct file *outfilp,
385 loff_t *ppos,
386 size_t count,
387 int flags,
388 int ioflags,
389 cred_t *credp)
390 {
391 xfs_inode_t *ip = XFS_BHVTOI(bdp);
392 xfs_mount_t *mp = ip->i_mount;
393 ssize_t ret;
394 struct inode *inode = outfilp->f_mapping->host;
395 xfs_fsize_t isize;
396
397 XFS_STATS_INC(xs_write_calls);
398 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
399 return -EIO;
400
401 xfs_ilock(ip, XFS_IOLOCK_EXCL);
402
403 if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_WRITE) &&
404 (!(ioflags & IO_INVIS))) {
405 bhv_vrwlock_t locktype = VRWLOCK_WRITE;
406 int error;
407
408 error = XFS_SEND_DATA(mp, DM_EVENT_WRITE, BHV_TO_VNODE(bdp),
409 *ppos, count,
410 FILP_DELAY_FLAG(outfilp), &locktype);
411 if (error) {
412 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
413 return -error;
414 }
415 }
416 xfs_rw_enter_trace(XFS_SPLICE_WRITE_ENTER, &ip->i_iocore,
417 pipe, count, *ppos, ioflags);
418 ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
419 if (ret > 0)
420 XFS_STATS_ADD(xs_write_bytes, ret);
421
422 isize = i_size_read(inode);
423 if (unlikely(ret < 0 && ret != -EFAULT && *ppos > isize))
424 *ppos = isize;
425
426 if (*ppos > ip->i_d.di_size) {
427 xfs_ilock(ip, XFS_ILOCK_EXCL);
428 if (*ppos > ip->i_d.di_size) {
429 ip->i_d.di_size = *ppos;
430 i_size_write(inode, *ppos);
431 ip->i_update_core = 1;
432 ip->i_update_size = 1;
433 }
434 xfs_iunlock(ip, XFS_ILOCK_EXCL);
435 }
436 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
437 return ret;
438 }
439
440 /*
441 * This routine is called to handle zeroing any space in the last
442 * block of the file that is beyond the EOF. We do this since the
443 * size is being increased without writing anything to that block
444 * and we don't want anyone to read the garbage on the disk.
445 */
446 STATIC int /* error (positive) */
447 xfs_zero_last_block(
448 struct inode *ip,
449 xfs_iocore_t *io,
450 xfs_fsize_t isize,
451 xfs_fsize_t end_size)
452 {
453 xfs_fileoff_t last_fsb;
454 xfs_mount_t *mp = io->io_mount;
455 int nimaps;
456 int zero_offset;
457 int zero_len;
458 int error = 0;
459 xfs_bmbt_irec_t imap;
460 loff_t loff;
461
462 ASSERT(ismrlocked(io->io_lock, MR_UPDATE) != 0);
463
464 zero_offset = XFS_B_FSB_OFFSET(mp, isize);
465 if (zero_offset == 0) {
466 /*
467 * There are no extra bytes in the last block on disk to
468 * zero, so return.
469 */
470 return 0;
471 }
472
473 last_fsb = XFS_B_TO_FSBT(mp, isize);
474 nimaps = 1;
475 error = XFS_BMAPI(mp, NULL, io, last_fsb, 1, 0, NULL, 0, &imap,
476 &nimaps, NULL, NULL);
477 if (error) {
478 return error;
479 }
480 ASSERT(nimaps > 0);
481 /*
482 * If the block underlying isize is just a hole, then there
483 * is nothing to zero.
484 */
485 if (imap.br_startblock == HOLESTARTBLOCK) {
486 return 0;
487 }
488 /*
489 * Zero the part of the last block beyond the EOF, and write it
490 * out sync. We need to drop the ilock while we do this so we
491 * don't deadlock when the buffer cache calls back to us.
492 */
493 XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL| XFS_EXTSIZE_RD);
494
495 loff = XFS_FSB_TO_B(mp, last_fsb);
496 zero_len = mp->m_sb.sb_blocksize - zero_offset;
497 error = xfs_iozero(ip, loff + zero_offset, zero_len, end_size);
498
499 XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
500 ASSERT(error >= 0);
501 return error;
502 }
503
504 /*
505 * Zero any on disk space between the current EOF and the new,
506 * larger EOF. This handles the normal case of zeroing the remainder
507 * of the last block in the file and the unusual case of zeroing blocks
508 * out beyond the size of the file. This second case only happens
509 * with fixed size extents and when the system crashes before the inode
510 * size was updated but after blocks were allocated. If fill is set,
511 * then any holes in the range are filled and zeroed. If not, the holes
512 * are left alone as holes.
513 */
514
515 int /* error (positive) */
516 xfs_zero_eof(
517 bhv_vnode_t *vp,
518 xfs_iocore_t *io,
519 xfs_off_t offset, /* starting I/O offset */
520 xfs_fsize_t isize, /* current inode size */
521 xfs_fsize_t end_size) /* terminal inode size */
522 {
523 struct inode *ip = vn_to_inode(vp);
524 xfs_fileoff_t start_zero_fsb;
525 xfs_fileoff_t end_zero_fsb;
526 xfs_fileoff_t zero_count_fsb;
527 xfs_fileoff_t last_fsb;
528 xfs_mount_t *mp = io->io_mount;
529 int nimaps;
530 int error = 0;
531 xfs_bmbt_irec_t imap;
532
533 ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
534 ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
535 ASSERT(offset > isize);
536
537 /*
538 * First handle zeroing the block on which isize resides.
539 * We only zero a part of that block so it is handled specially.
540 */
541 error = xfs_zero_last_block(ip, io, isize, end_size);
542 if (error) {
543 ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
544 ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
545 return error;
546 }
547
548 /*
549 * Calculate the range between the new size and the old
550 * where blocks needing to be zeroed may exist. To get the
551 * block where the last byte in the file currently resides,
552 * we need to subtract one from the size and truncate back
553 * to a block boundary. We subtract 1 in case the size is
554 * exactly on a block boundary.
555 */
556 last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
557 start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
558 end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
559 ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
560 if (last_fsb == end_zero_fsb) {
561 /*
562 * The size was only incremented on its last block.
563 * We took care of that above, so just return.
564 */
565 return 0;
566 }
567
568 ASSERT(start_zero_fsb <= end_zero_fsb);
569 while (start_zero_fsb <= end_zero_fsb) {
570 nimaps = 1;
571 zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
572 error = XFS_BMAPI(mp, NULL, io, start_zero_fsb, zero_count_fsb,
573 0, NULL, 0, &imap, &nimaps, NULL, NULL);
574 if (error) {
575 ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
576 ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
577 return error;
578 }
579 ASSERT(nimaps > 0);
580
581 if (imap.br_state == XFS_EXT_UNWRITTEN ||
582 imap.br_startblock == HOLESTARTBLOCK) {
583 /*
584 * This loop handles initializing pages that were
585 * partially initialized by the code below this
586 * loop. It basically zeroes the part of the page
587 * that sits on a hole and sets the page as P_HOLE
588 * and calls remapf if it is a mapped file.
589 */
590 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
591 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
592 continue;
593 }
594
595 /*
596 * There are blocks we need to zero.
597 * Drop the inode lock while we're doing the I/O.
598 * We'll still have the iolock to protect us.
599 */
600 XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
601
602 error = xfs_iozero(ip,
603 XFS_FSB_TO_B(mp, start_zero_fsb),
604 XFS_FSB_TO_B(mp, imap.br_blockcount),
605 end_size);
606 if (error) {
607 goto out_lock;
608 }
609
610 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
611 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
612
613 XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
614 }
615
616 return 0;
617
618 out_lock:
619
620 XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
621 ASSERT(error >= 0);
622 return error;
623 }
624
625 ssize_t /* bytes written, or (-) error */
626 xfs_write(
627 bhv_desc_t *bdp,
628 struct kiocb *iocb,
629 const struct iovec *iovp,
630 unsigned int nsegs,
631 loff_t *offset,
632 int ioflags,
633 cred_t *credp)
634 {
635 struct file *file = iocb->ki_filp;
636 struct address_space *mapping = file->f_mapping;
637 struct inode *inode = mapping->host;
638 unsigned long segs = nsegs;
639 xfs_inode_t *xip;
640 xfs_mount_t *mp;
641 ssize_t ret = 0, error = 0;
642 xfs_fsize_t isize, new_size;
643 xfs_iocore_t *io;
644 bhv_vnode_t *vp;
645 unsigned long seg;
646 int iolock;
647 int eventsent = 0;
648 bhv_vrwlock_t locktype;
649 size_t ocount = 0, count;
650 loff_t pos;
651 int need_i_mutex = 1, need_flush = 0;
652
653 XFS_STATS_INC(xs_write_calls);
654
655 vp = BHV_TO_VNODE(bdp);
656 xip = XFS_BHVTOI(bdp);
657
658 for (seg = 0; seg < segs; seg++) {
659 const struct iovec *iv = &iovp[seg];
660
661 /*
662 * If any segment has a negative length, or the cumulative
663 * length ever wraps negative then return -EINVAL.
664 */
665 ocount += iv->iov_len;
666 if (unlikely((ssize_t)(ocount|iv->iov_len) < 0))
667 return -EINVAL;
668 if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
669 continue;
670 if (seg == 0)
671 return -EFAULT;
672 segs = seg;
673 ocount -= iv->iov_len; /* This segment is no good */
674 break;
675 }
676
677 count = ocount;
678 pos = *offset;
679
680 if (count == 0)
681 return 0;
682
683 io = &xip->i_iocore;
684 mp = io->io_mount;
685
686 vfs_wait_for_freeze(vp->v_vfsp, SB_FREEZE_WRITE);
687
688 if (XFS_FORCED_SHUTDOWN(mp))
689 return -EIO;
690
691 if (ioflags & IO_ISDIRECT) {
692 xfs_buftarg_t *target =
693 (xip->i_d.di_flags & XFS_DIFLAG_REALTIME) ?
694 mp->m_rtdev_targp : mp->m_ddev_targp;
695
696 if ((pos & target->bt_smask) || (count & target->bt_smask))
697 return XFS_ERROR(-EINVAL);
698
699 if (!VN_CACHED(vp) && pos < i_size_read(inode))
700 need_i_mutex = 0;
701
702 if (VN_CACHED(vp))
703 need_flush = 1;
704 }
705
706 relock:
707 if (need_i_mutex) {
708 iolock = XFS_IOLOCK_EXCL;
709 locktype = VRWLOCK_WRITE;
710
711 mutex_lock(&inode->i_mutex);
712 } else {
713 iolock = XFS_IOLOCK_SHARED;
714 locktype = VRWLOCK_WRITE_DIRECT;
715 }
716
717 xfs_ilock(xip, XFS_ILOCK_EXCL|iolock);
718
719 isize = i_size_read(inode);
720
721 if (file->f_flags & O_APPEND)
722 *offset = isize;
723
724 start:
725 error = -generic_write_checks(file, &pos, &count,
726 S_ISBLK(inode->i_mode));
727 if (error) {
728 xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
729 goto out_unlock_mutex;
730 }
731
732 new_size = pos + count;
733 if (new_size > isize)
734 io->io_new_size = new_size;
735
736 if ((DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_WRITE) &&
737 !(ioflags & IO_INVIS) && !eventsent)) {
738 loff_t savedsize = pos;
739 int dmflags = FILP_DELAY_FLAG(file);
740
741 if (need_i_mutex)
742 dmflags |= DM_FLAGS_IMUX;
743
744 xfs_iunlock(xip, XFS_ILOCK_EXCL);
745 error = XFS_SEND_DATA(xip->i_mount, DM_EVENT_WRITE, vp,
746 pos, count,
747 dmflags, &locktype);
748 if (error) {
749 xfs_iunlock(xip, iolock);
750 goto out_unlock_mutex;
751 }
752 xfs_ilock(xip, XFS_ILOCK_EXCL);
753 eventsent = 1;
754
755 /*
756 * The iolock was dropped and reacquired in XFS_SEND_DATA
757 * so we have to recheck the size when appending.
758 * We will only "goto start;" once, since having sent the
759 * event prevents another call to XFS_SEND_DATA, which is
760 * what allows the size to change in the first place.
761 */
762 if ((file->f_flags & O_APPEND) && savedsize != isize) {
763 pos = isize = xip->i_d.di_size;
764 goto start;
765 }
766 }
767
768 if (likely(!(ioflags & IO_INVIS))) {
769 file_update_time(file);
770 xfs_ichgtime_fast(xip, inode,
771 XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
772 }
773
774 /*
775 * If the offset is beyond the size of the file, we have a couple
776 * of things to do. First, if there is already space allocated
777 * we need to either create holes or zero the disk or ...
778 *
779 * If there is a page where the previous size lands, we need
780 * to zero it out up to the new size.
781 */
782
783 if (pos > isize) {
784 error = xfs_zero_eof(BHV_TO_VNODE(bdp), io, pos,
785 isize, pos + count);
786 if (error) {
787 xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
788 goto out_unlock_mutex;
789 }
790 }
791 xfs_iunlock(xip, XFS_ILOCK_EXCL);
792
793 /*
794 * If we're writing the file then make sure to clear the
795 * setuid and setgid bits if the process is not being run
796 * by root. This keeps people from modifying setuid and
797 * setgid binaries.
798 */
799
800 if (((xip->i_d.di_mode & S_ISUID) ||
801 ((xip->i_d.di_mode & (S_ISGID | S_IXGRP)) ==
802 (S_ISGID | S_IXGRP))) &&
803 !capable(CAP_FSETID)) {
804 error = xfs_write_clear_setuid(xip);
805 if (likely(!error))
806 error = -remove_suid(file->f_dentry);
807 if (unlikely(error)) {
808 xfs_iunlock(xip, iolock);
809 goto out_unlock_mutex;
810 }
811 }
812
813 retry:
814 /* We can write back this queue in page reclaim */
815 current->backing_dev_info = mapping->backing_dev_info;
816
817 if ((ioflags & IO_ISDIRECT)) {
818 if (need_flush) {
819 xfs_inval_cached_trace(io, pos, -1,
820 ctooff(offtoct(pos)), -1);
821 bhv_vop_flushinval_pages(vp, ctooff(offtoct(pos)),
822 -1, FI_REMAPF_LOCKED);
823 }
824
825 if (need_i_mutex) {
826 /* demote the lock now the cached pages are gone */
827 XFS_ILOCK_DEMOTE(mp, io, XFS_IOLOCK_EXCL);
828 mutex_unlock(&inode->i_mutex);
829
830 iolock = XFS_IOLOCK_SHARED;
831 locktype = VRWLOCK_WRITE_DIRECT;
832 need_i_mutex = 0;
833 }
834
835 xfs_rw_enter_trace(XFS_DIOWR_ENTER, io, (void *)iovp, segs,
836 *offset, ioflags);
837 ret = generic_file_direct_write(iocb, iovp,
838 &segs, pos, offset, count, ocount);
839
840 /*
841 * direct-io write to a hole: fall through to buffered I/O
842 * for completing the rest of the request.
843 */
844 if (ret >= 0 && ret != count) {
845 XFS_STATS_ADD(xs_write_bytes, ret);
846
847 pos += ret;
848 count -= ret;
849
850 need_i_mutex = 1;
851 ioflags &= ~IO_ISDIRECT;
852 xfs_iunlock(xip, iolock);
853 goto relock;
854 }
855 } else {
856 xfs_rw_enter_trace(XFS_WRITE_ENTER, io, (void *)iovp, segs,
857 *offset, ioflags);
858 ret = generic_file_buffered_write(iocb, iovp, segs,
859 pos, offset, count, ret);
860 }
861
862 current->backing_dev_info = NULL;
863
864 if (ret == -EIOCBQUEUED && !(ioflags & IO_ISAIO))
865 ret = wait_on_sync_kiocb(iocb);
866
867 if ((ret == -ENOSPC) &&
868 DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_NOSPACE) &&
869 !(ioflags & IO_INVIS)) {
870
871 xfs_rwunlock(bdp, locktype);
872 if (need_i_mutex)
873 mutex_unlock(&inode->i_mutex);
874 error = XFS_SEND_NAMESP(xip->i_mount, DM_EVENT_NOSPACE, vp,
875 DM_RIGHT_NULL, vp, DM_RIGHT_NULL, NULL, NULL,
876 0, 0, 0); /* Delay flag intentionally unused */
877 if (error)
878 goto out_nounlocks;
879 if (need_i_mutex)
880 mutex_lock(&inode->i_mutex);
881 xfs_rwlock(bdp, locktype);
882 pos = xip->i_d.di_size;
883 ret = 0;
884 goto retry;
885 }
886
887 isize = i_size_read(inode);
888 if (unlikely(ret < 0 && ret != -EFAULT && *offset > isize))
889 *offset = isize;
890
891 if (*offset > xip->i_d.di_size) {
892 xfs_ilock(xip, XFS_ILOCK_EXCL);
893 if (*offset > xip->i_d.di_size) {
894 xip->i_d.di_size = *offset;
895 i_size_write(inode, *offset);
896 xip->i_update_core = 1;
897 xip->i_update_size = 1;
898 }
899 xfs_iunlock(xip, XFS_ILOCK_EXCL);
900 }
901
902 error = -ret;
903 if (ret <= 0)
904 goto out_unlock_internal;
905
906 XFS_STATS_ADD(xs_write_bytes, ret);
907
908 /* Handle various SYNC-type writes */
909 if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) {
910 error = xfs_write_sync_logforce(mp, xip);
911 if (error)
912 goto out_unlock_internal;
913
914 xfs_rwunlock(bdp, locktype);
915 if (need_i_mutex)
916 mutex_unlock(&inode->i_mutex);
917
918 error = sync_page_range(inode, mapping, pos, ret);
919 if (!error)
920 error = ret;
921 return error;
922 }
923
924 out_unlock_internal:
925 xfs_rwunlock(bdp, locktype);
926 out_unlock_mutex:
927 if (need_i_mutex)
928 mutex_unlock(&inode->i_mutex);
929 out_nounlocks:
930 return -error;
931 }
932
933 /*
934 * All xfs metadata buffers except log state machine buffers
935 * get this attached as their b_bdstrat callback function.
936 * This is so that we can catch a buffer
937 * after prematurely unpinning it to forcibly shutdown the filesystem.
938 */
939 int
940 xfs_bdstrat_cb(struct xfs_buf *bp)
941 {
942 xfs_mount_t *mp;
943
944 mp = XFS_BUF_FSPRIVATE3(bp, xfs_mount_t *);
945 if (!XFS_FORCED_SHUTDOWN(mp)) {
946 xfs_buf_iorequest(bp);
947 return 0;
948 } else {
949 xfs_buftrace("XFS__BDSTRAT IOERROR", bp);
950 /*
951 * Metadata write that didn't get logged but
952 * written delayed anyway. These aren't associated
953 * with a transaction, and can be ignored.
954 */
955 if (XFS_BUF_IODONE_FUNC(bp) == NULL &&
956 (XFS_BUF_ISREAD(bp)) == 0)
957 return (xfs_bioerror_relse(bp));
958 else
959 return (xfs_bioerror(bp));
960 }
961 }
962
963
964 int
965 xfs_bmap(bhv_desc_t *bdp,
966 xfs_off_t offset,
967 ssize_t count,
968 int flags,
969 xfs_iomap_t *iomapp,
970 int *niomaps)
971 {
972 xfs_inode_t *ip = XFS_BHVTOI(bdp);
973 xfs_iocore_t *io = &ip->i_iocore;
974
975 ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG);
976 ASSERT(((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) != 0) ==
977 ((ip->i_iocore.io_flags & XFS_IOCORE_RT) != 0));
978
979 return xfs_iomap(io, offset, count, flags, iomapp, niomaps);
980 }
981
982 /*
983 * Wrapper around bdstrat so that we can stop data
984 * from going to disk in case we are shutting down the filesystem.
985 * Typically user data goes thru this path; one of the exceptions
986 * is the superblock.
987 */
988 int
989 xfsbdstrat(
990 struct xfs_mount *mp,
991 struct xfs_buf *bp)
992 {
993 ASSERT(mp);
994 if (!XFS_FORCED_SHUTDOWN(mp)) {
995 /* Grio redirection would go here
996 * if (XFS_BUF_IS_GRIO(bp)) {
997 */
998
999 xfs_buf_iorequest(bp);
1000 return 0;
1001 }
1002
1003 xfs_buftrace("XFSBDSTRAT IOERROR", bp);
1004 return (xfs_bioerror_relse(bp));
1005 }
1006
1007 /*
1008 * If the underlying (data/log/rt) device is readonly, there are some
1009 * operations that cannot proceed.
1010 */
1011 int
1012 xfs_dev_is_read_only(
1013 xfs_mount_t *mp,
1014 char *message)
1015 {
1016 if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
1017 xfs_readonly_buftarg(mp->m_logdev_targp) ||
1018 (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
1019 cmn_err(CE_NOTE,
1020 "XFS: %s required on read-only device.", message);
1021 cmn_err(CE_NOTE,
1022 "XFS: write access unavailable, cannot proceed.");
1023 return EROFS;
1024 }
1025 return 0;
1026 }
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